1. Field of the Invention
The present invention relates to a semiconductor device and a method of manufacturing the semiconductor device.
2. Description of the Background Art
Power modules are used for motor control of industrial devices and consumer devices. In the conventional general power module, a substrate having a semiconductor element mounted thereon and a casing made of a thermoplastic resin and used as a housing are bonded with an adhesive or the like. Also, the space within the casing and above the semiconductor element is sealed with silicone gel or the like. Furthermore, the semiconductor element and the circuit wiring on the substrate are connected via wire bond connection.
In the method of manufacturing this power module, an adhesive is applied to a substrate or a casing, and hardened to bond the substrate and the casing to each other. Then, the space within the casing is sealed with silicone gel or the like.
Furthermore, for example, Japanese Patent Laying-Open No. 2010-129797 proposes a power semiconductor device in which a power semiconductor module sealed with a transfer mold resin is set in an insert case. In this power semiconductor device, the first and second external terminals provided in the ceiling portion of the insert case are inserted into a cylindrical conductive body of the power semiconductor module, so that the power semiconductor module is set in the insert case.
Furthermore, for example, Japanese Patent Laying-Open No. 2010-087002 proposes a heat-generating component cooling structure in which a semiconductor module is installed in a cooling case. In this heat-generating component cooling structure, a protruding portion of the semiconductor module is inserted into the opening of the cooling case so as to ensure the sealing properties.
In the conventional general power module, the bonding portion between the semiconductor element and the wire is cut by thermal stress caused by thermal expansion and thermal contraction of silicone gel, which causes a problem that the life of the power module may be shortened.
Furthermore, according to this method of manufacturing a power module, an adhesive is applied to a substrate or a casing, and hardened to bond the substrate and the casing to each other, and then, the space within the casing is sealed with silicone gel, which causes a problem that the number of processes is increased. There is also a problem that the manufacturing cost is also increased. Furthermore, in order to prevent silicone gel from leaking to the outside of the casing from the portion where the adhesive is not applied, it is necessary to apply an adhesive to the entire periphery of the substrate without having any gap left thereon. This causes a problem of taking much time and effort, which also leads to a problem that productivity is decreased.
Furthermore, in the power semiconductor device disclosed in Japanese Patent Laying-Open No. 2010-129797, it is necessary to form the first and second external terminals in a press-fit structure so as to be inserted into the cylindrical conductive body. This causes a problem that productivity is decreased.
Furthermore, in the heat-generating component cooling structure disclosed in Japanese Patent Laying-Open No. 2010-087002, it is necessary to provide an opening in the cooling case and a protruding portion in the semiconductor module. Furthermore, since the protruding portion is inserted into the opening so as to ensure the sealing properties, the opening and the protruding portion are joined to each other through surface contact. This makes it difficult to insert the protruding portion into the opening, which leads to a problem that productivity is decreased.